Novel arsenic biosensor “POLA” obtained by a genetically modified E. coli bioreporter cell

Abstract

In this paper, we present a new vector named vector total POLA (VtP), which senses arsenite as input signal, and has a signal amplifier in order to express a green fluorescent protein as a response. This vector functions in the bacterium E. coli K-12. It is demonstrated that the fluorescence signal at 530nm of the living arsenic biosensor increases linearly with elapsed time and as arsenite concentration increases. The range has been proven to detect from 5 to 140μg/l of arsenite. An experiment was carried out to determine the kinetic response of the bacterial biosensor as a function of arsenite concentration for 12h, which confirmed that the development of the new vector produce a well-defined linear response as fluorescence. This measurement can be carried out in as little as 1h at different concentrations of arsenite. A preliminary test where the bacterial biosensor was coupled with an optical fiber was performed in order to investigate the possibility of its integration as an optical fiber biosensor in the near future. The optical power output also presented a linear dependency on arsenite concentration.